The present invention relates to a new and improved construction of a vertical tool head for the headstock of a horizontal drilling-milling machine, which vertical tool head is of the type carried by a support arm disposed above and displaceable substantially parallel to a horizontal tool spindle and can be clamped in a work position at a headstock projection and drivable by the horizontal tool spindle which is mounted at the headstock projection.
There are already known to the art headstocks of larger size horizontal drilling-milling machines equipped with a support arm, at the front end of which there can be mounted, depending upon requirements, different types of tool heads driven by the horizontal tool spindle, in order to make more universal the employment of the machine. When working with the horizontal tool spindle the tool heads are dismantled. The chucking and releasing of the tools at the tool heads is carried out manually. There is not possible any coordinated automatic mode of operation of the horizontal tool spindle and the tool heads, especially when working with a tool changer.
The headstocks of larger plate-drilling-milling devices are sometimes equipped with a lower arm displaceable parallel to the horizontal tool spindle, at the front end of which there is non-detachably mounted an angular milling head which can be rotated through 360.degree.. Its milling spindle is driven by spindle gearing located at the rear end of the lower arm and the lower arm can carry out, by means of a feed drive, milling operations in the direction of the horizontal tool spindle with random angular positions of the angular milling head. Due to the arrangement of the lower arm beneath the headstock the lowest position of the headstock is limited and in the uppermost headstock position the milling spindle does not reach the upper working region of the horizontal tool spindle. The chucking and release of the tools used in the angular milling head only can be manually carried out because of constructional and spatial reasons governed by the work conditions. There is not possible any coordinated automatic mode of operation of the horizontal tool spindle and the milling spindle, especially in conjunction with a tool changer. Due to the special drive required for the milling spindle and owing to the lower arm-feed drive there is a considerably greater structural expenditure, limiting the use of the equipment to large plate drilling-milling devices.
Box-shaped workpieces of small and intermediate size are machined upon a horizontal drilling-milling machine with a workpiece table which can be indexed four times through 90.degree. and with an associated vertical drilling-milling machine. The machining of the four vertical sides of the workpiece, during mass production, is carried out at the horizontal drilling-milling machine equipped with an automatic tool changer and the machining of the horizontal fifth side of the workpiece is carried out at the vertical drilling-milling machine likewise equipped with an automatic tool changer. Depending upon the nature of the degree of automation the chucking of the workpiece from one machine at the other is carried out manually or, if both machines are interlinked into a production line or system, by automatic pallet transports. With a work technique employing two non-interlinked machines there is a greater loss in time due to the manually actuated workpiece transport as well as owing to the required alignment and chucking of the workpiece at each machine. The required investment expenditure consists of:
a. a horizontal machine; PA1 b. a horizontal tool changer with a set of tools; PA1 c. a vertical machine; PA1 d. a vertical tool changer with a set of tools.
In a production system using two interlinked machines and an automatic pallet transport there exists a considerably greater investment expenditure which is only economical in very few manufacturing facilities.
At smaller universal milling machines equipped with a horizontal tool spindle the vertical machining operations are carried out by a vertical tool head pivotably mounted at the machine. The thus employed constructions are not suitable for horizontal drilling-milling machines of the present type under consideration, at which the horizontal tool spindle is mounted in a projection of the vertically displaceable headstock, in order to achieve a free overhang above the workpiece table in conjunction with a tool changer which operates automatically.